Detection Of ALK Gene Mutation In Non-small Cell Lung Cancer Patients By Immunohistochemistry

Objective With RT-PCR as a reference,detection of ALK gene mutation through immunohistochemistry in NSCLC patients,is aimed to explore an economically viable detection method and investigate the clinical and pathological features of ALK-positive patientsMethods By using rabbit monoclonal D5F3 antibody, ALK IHC was performed on 234 NSCLC patients. positive cases were confirmed by RT-PCR.Results 1. The positive incidence of ALK by IHC in 234 tissue specimens was 8.97%(21/234), the mutation rate after verification by RT-PCR was 5.98%(14/234); 2. There is significant difference with histological type, age, stage-related(P <0.05); but no significant difference with gender, smoking history, tumor differentiation. 3. 21 cases of patients were RT-PCR validation, IHC and RT-PCR in line with the rate of increase with increasing degree of IHC-positive. When IHC1 + both the rate was 0, when IHC3 + or immunohistochemical score> 120, both the rate was 100%.Conclusion 1. Our findings demonstrate that ALK rearrangements tended to be present in NSCLC patients with adenocarcinoma, no smokinghabit, younger age and advanced, has nothing to do with sex, smoking history, tumor differentiation degree. 2.Although immunohistochemical expression of ALK fusion gene exists a certain falsepositive, but IHC3 + or immunohistochemical score> 120 with high-value diagnostic confirmation, is a reliable method to screening ALK in lung cancer. 3.detection of ALK-positive lung cancer by IHC screening and subsequent RT-PCR confirmation is economically and viable.